A spontaneous 9/11 memorial that sprung up at a West Village lot a day after the attacks will be incorporated into the exterior of a new MTA ventilation plant going up on the site, renderings obtained by The Post show.

But even with the inclusion of Tiles for America — thousands of ceramic squares hung on a fence on Greenwich Avenue and Seventh Avenue South — some community leaders are still unhappy with the building’s final design, crafted to please locals in the landmarked neighborhood.

“It looks like a brick-faced tomb,” said Andrew Berman, executive director of the Greenwich Village Society for Historic Preservation.

Because the MTA owns the vacant lot and is a state agency, it does not need approval from the city’s Landmark Preservation Committee to erect the plant, designed by in-house architects.

Officials expect to break ground soon, and the entire project should be completed in less than four years.

Portions of Tiles for America — which started as a cluster of angel figures tied to a fence and morphed into thousands of ceramic squares honoring the dead — will be placed on the lower exterior wall of the plant.

The first angels were hung with ribbons as get-well-soon messages for the wounded people expected to be brought to the now-shuttered St. Vincent’s Hospital located across the street.

But the high number of casualties instead turned the site into a place to pay tribute to the dead, said Lorrie Veasey, the artist who started the memorial next to her Our Name is Mud pottery studio.

She said she is happy the tiles will remain.

“For years, [the MTA] helped take care of it. It was inconvenient for them, but they were wonderful about it,” Veasey recalled.

MTA spokesman Kevin Ortiz said officials worked hard to make locals happy, even scrapping plans for a tower deemed too ugly.

In response to those who call the final design ugly, he said, “We respectfully disagree.”